Differentiation hypotheses concern changes in the structural organization of cognitive abilities that depend on the level of general intelligence (ability differentiation) or age (developmental differentiation). Part 1 of this article presents a review of the literature on ability and developmental differentiation effects in children, revealing…

Twins regularly score nearly a standard deviation below the population mean on standardized measures of cognitive development in infancy but recover to the population mean by early childhood, making rapid gains through the toddler years. To date, only polynomial growth models have been fit to model cognitive recovery across childhood, limiting the…

Differentiation of intelligence refers to changes in the structure of intelligence that depend on individuals' level of general cognitive ability (ability differentiation hypothesis) or age (developmental differentiation hypothesis). The present article aimed to investigate ability differentiation, developmental differentiation, and their…

How we feel about an outcome often depends on how close an alternative outcome was to occurring. In four experiments, we investigated whether predominantly White, middle-class, Canadian children (N = 425, Experiments 1-3) and American adults (N = 227, Experiment 4) consider close counterfactual alternatives when inferring other people's emotions.…

The ability to recognize and label emotions serves as a building block by which children make sense of the world and learn how to interact with social partners. However, the timing and salience of influences on emotion recognition development are not fully understood. Path analyses evaluated the contributions of parenting and child narrative…

HIV-exposed uninfected (HEU) children during the preschool and early school ages may be at-risk for neurodevelopmental challenges due to in utero and perinatal exposure to HIV and/or antiretroviral (ARV) medications. HEU children and HIV-unexposed uninfected (HUU) children from the community were recruited and tested at 3 to 4 and 5 to 6 years of…

Recent studies indicate that premature children are at risk for difficulties with cognitive development and have increased incidence of ADHD as well as other behavioral disorders. Although the exact mechanism accounting for these children's neuropsychological abnormalities is unknown, there is evidence to suggest that the cognitive and behavioral…

A wealth of literature has examined the association between breastfeeding and the development of cognitive abilities in childhood. In particular, at least some evidence exists suggesting that breastfed children perform better on measures of intelligence later in life. Although a correlation appears to be present, fewer observational studies have…

Guided by evolutionary-developmental models, this study tested the hypothesis that children's exposure to parental relationship instability, defined by initiation and dissolution of caregiver intimate relationships, has both costs in cognitive impairments and benefits in enhanced learning skills. Participants included 243 mothers and their…

Neurological soft signs (NSSs), minor neurological abnormalities, have been implicated as risk factors for poor cognitive performance in small-scale studies. Here we investigate the associations between NSSs and multiple domains of cognitive performance in a large, population-based cohort and evaluate sex differences in these associations. We…

Throughout childhood and adolescence, humans experience marked changes in cortical structure and cognitive ability. Cortical thickness and surface area, in particular, have been associated with cognitive ability. Here we ask the question: What are the time-related associations between cognitive changes and cortical structure maturation.…

Reading acquisition is based on a set of preliteracy skills that lay the foundation for future reading abilities. Phonological awareness--the ability to identify and manipulate the sound units of oral language--has been reported to play a central role in reading acquisition. However, current evidence is mixed with respect to its universal…

Children start preschool with large individual differences in their early numerical abilities. Little is known about the importance of heterogeneous patterns that exist within these individual differences. A person-centered analytic approach might be helpful to unravel these patterns and the cognitive and environmental factors that are associated…

Previous research has shown that home environment plays an important role in children's early language skills. Yet, few researchers have examined the unique role of family-level factors (socioeconomic status [SES], household chaos) on children's learning or focused on the longitudinal processes that might explain their relations to children's…

At the beginning of preschool (M = 46 months of age), 197 (94 boys) children were administered tasks that assessed a suite of nonsymbolic and symbolic quantitative competencies as well as their executive functions, verbal and nonverbal intelligence, preliteracy skills, and their parents' education level. The children's mathematics achievement was…